Commutator-brush holder.



m w m, n e D d e t n e t a P R. E DJ L1 .Uw DH1, Munn SNF Lm NN LRE .BwwR JAM EN w Hfw U um MN M ...uu

@mi w\\ Nm? @E NN. uw 2 )N 1\\%Nl\ 4, 8 m .m .N MN o. ,u N M @NEN WimwJwzyffgw MW.

zo to avoid cutting.

UNITED STATES PATENT OFFICE.

HARRY J. IV. LLOYD, OF DES MOINES, IOVA.

COMMUTATOR-BRUSH HOLDER.

SPECIFICATION forming part of Letters Patent N o. 688,423, datedDecember 10, 1901.

Application filed February 11,1901. Serial No. 46,795. (No model.)

To @ZZ whom it may concern:

Be it known that I, HARRY J. W. LLoYD, a

subject of the King of Great Britain, residing at Des Moines, county ofPolk, and State of Iowa, have invented certain new and useful xo areused to contact with the commutator.

My objects are, first, to provide a brushholder of this class of simple,durable, and inexpensive construction, in which an independent pressuredevice is provided for each pencil, said pressure device being soarranged as to be capable of supplying a very slight pressure to the topof the pencil to hold it firmly in contact with the commutator, and yetbear upon the commutator so lightly as In this connection it is to beremembered that carbons gradually wear away by use, and a further objectalong this line is to provide means whereby the tension of the yieldingpressure device for each carbon may be readily and quickly adjustedwhile the device is in operation, so that substantially the samepressure may be main tained when the pencils are of any length.

A further object is to provide means in a 5o device of this classwhereby the current may be applied to or taken from the carbons directwithout passing through joints or other devices not forming goodconductors; and my object is,further,in this connection to provideyielding pressure devices for the carbons which are not liable todeterioration on account of having an electric current pass through thesprings of the yielding pressure device; and my object is, further, toprovide a 4o device of this class in which the yielding prestion of thevarious parts of the device whereby the objects contemplated areattained, as hereinafter more fully setforth, pointed out in my claims,and illustrated in the accompanying drawings, in which- Figure 1 shows atop or plan view of the complete brush-holder, with a portion of one ofthe yielding pressure devices broken away to show its interiorconstruction. Fig.2 shows a vertical sectional view through theindicated line 2 2 of Fig. 1. Fig. 3 shows in perspective one of thearms to be actuated by the spring for applying the yielding pressure tothe tops of the carbon pencils.

Referring to the accompanying drawings, I have used thereference-numeral 10 to indicate the body portion or frameof thebrushholder. One end portion of the frame is provided with the screwthreaded shank 1l, whereby it may be connected with a portion of themachine-frame.

In the body portion 10 is a series of vertical openings of a size toadmit carbon pencils of the size usually employed in arc-lamps. Theseopenings are preferably arranged in two parallel rows, with the holes ofone row arranged between the holes of the adjacent row for purposeshereinafter made clear.

At one side of the main portion of the frame 10 are the extensions 12 atopposite end portions of the frame. In each of these extensions is anupright 13, screw-threaded at its upper portion, and mounted upon theseuprights, with the sleeves 14, are the frames 15. These frames support across-bar 16, which is iixed in said frames by means of the pins 17.Near the top portion of each of the sleeves 14 is a slot 18, and a nut19 is placed in said slot and in engagement with the screw-threads ofthe rods 13. Hence when said nuts are turned the sleeves 14: will bemoved vertically upon the rods 13. I have also preferably placed uponthe top of each rod 13 a lock-nut 2O to engage the top of the sleeve 14.By this means it is obvious that the bar 1G is adjustably supported in aposition parallel with and above the main portion of the frame 10.

The carbon pencils are of the Ordin ary kind and are indicated by thereference-numeral 21, one carbon being passed through each of theopenings in the frame 10. At the top of each carbon I have fitted ametal cap 22, and in each cap I have passed a conducting-wire 23 throughthe cap and between the top of the cap and the top of the carbon, andthe wire is flattened out on the interior of the cap, so that it cannotpull through the opening in the cap through which it was passed. Ipreferably place solder between the top of the cap and said Wire.

IOO

Attached to one side of the frame 10 is a bar 24, preferably made ofcopper or some other suitable conductor. 'lhe ends of said bar areelectrically connected with the body portion 10, and the central portionof the bar extends upwardly to a point at or near the upper limit ofmovement ot' the pencils. Each of the wires 23 is connected with saidbar and a setscrew 25, capable of being forced downwardly intoengagement with the end ofthe wire 23, a lock-nut 26 being placed onsaid set-screw to prevent it from working loose on account of thevibrations of the brush-holder. By this means it is obvious that thecurrent may pass from the body portion 10 to each pencil or from thepencils to the frame 10 through good electrical conductors and that nojoint or working parts appear in this continuity of electricalconductors, which would be liable to decrease the conductivity of theparts, and yet the free Vertical movement of the pencils is not in anyway interfered with.

The means for providing yielding pressure independently to the pencilscomprise an arm 27, having a tubular extension 28 at one end designed toadmit the bar 16 and be capable of rotary movement thereon. Somedistance from the eXterior'of the extension 2S is an annular rim 29 andprojecting in the same direction from the body portion of the arm 27,and in this rim is aseries of notches 30. The opposite end of the armprojects far enough to engage and rest upon the top of the correspondingpencil when the tubular extension 28 is on the bar 16. One of these armsis placed upon the bar 16 for each of the pen cils, and l have mountedupon each ot" the tubular extensions 2S a coil-spring 31. One end of thecoil-spring is bent downwardly to enteran opening in the bar 16. Thisprojecting end is indicated in Fig. 2 by the reterence-numeral 32. Theopposite end of the coi1-spring projects radially from the tubularextension 28 and then at right angles at 33 to form a handle and tooverlap the arm 27.

In practical use and assuming the bodyportion 10 to be secured to amotor or dynamo frame and the pencils 21 to be in engagement with acommutator, it is obvious that a continnity of good electricalconductors is established from each pencil to the body portion 10without having the current passed through a sliding or movable joint.Furthermore, any one of the pencils may be readily and quickly movedfrom the body portion 10 and a new one substituted therefor withoutstoppingthecommutator. Furthermore, ifacomparatively light pressure isdesired on top of each pencil the end 33 of the spring is per mitted torest upon the top of the arm 27, as shown in some of the parts ofFig. 1. If greater f pressure is desired, the end is grasped by theoperator and placed in one of v the slots 30, thereby winding up thespring l c. i

and increasing itsfpressure upon the arm. By this means a number ofdiiferent tensions may be applied to the arm 27 quickly and easily andwithout stopping the commutator. Vhen, however, the pencils have allbecome worn, so as to be materially shorter, the bar 16 may be loweredby a manipulation ol the nuts 19 and 20. Then it is desired to detachany one of the pencils, it is only necessary to loosen the set-screw 25,remove the wire 23 from the bar 2l, then elevate the arm H7 and bodilyremove the pencil. A new one may readily be substituted l'or the old byfitting it in the cap 22, from which the other pencil was taken.

lleretofore in devices of this class the only electrical connectionbetween the pencils and the body portion of the frame was had throughthe pivoted arm upon the stationary rod electrically conn eeted with theframe. In devices of this class the current has been required to jumpfrom one part to the other of the metal, and hence has frequently heatedthe metal in such manner as to materially weaken said part. Furthermore,where such electrical connection is relied on a current is frequentlyshort-circuited by jumping from the carbon direct to the body portion ofthe frame in which it is mounted. This also causes a heating of theparts and a consequent consuming, and the pencils in the frame arewholly or partially consumed, which obviously permits them to move intheir supports in the frame and causes what is known as chattering. Insome instances the arm 27 has been projected on the opposite side of thepivotal point, a contractile coil-spring attached thereto and secured toan elevated support. This has always been found objectionable for thereason that there is a tendency for the current to pass from the carbonpencils through the sprin g, which obviously would tend to weaken thespring if it became heated by the current, and if the support to whichthe springs are at; tached is made of any ordinary substance that is notan electrical conductor said substance will bend under the heat, andthereby weaken the pressure of the springs of the central pencils,causing them to wear unevenly upon the commutator.

Having thus described my invention, what I claim, and desire to secureby Letters Patent of the United States therefor, is-- 1. An improvedcotnlnutator-brush holder com prisingin combination a body portionhaving a number of openings therein, a series of carbon pencilsslidingly mounted in said openings, uprights connected with the bodypor-A tion, a bar -vertically adjustable on said up-V rights, a seriesof arms pivotally mounted on the bar and designed to engage the tops ofthe carbon pencils, an independent yielding pressure device to engageeach arm, independent means for adj'ustingthe tension of each spring,and an independent electric conductor connected with each carbon penciland with the body portion of the machine, for the purposes stated.

2. An improved commutator-brush holder, comprisingin combinationabodyportion hav- IOO IIC

l i i ing a number of openings therein, a series of carbon pencilsslidingly mounted in said openings, uprights supported at one side ofthe body portion, a bar 16 adjustable vertically upon said uprights, aseries of arms 27 having tubular extensions 28, rims 29 and notches 30in said rims, loosely mounted upon said bar 16, a coil-spring mountedupon each of the tubular extensions 28, and having one end fixed to thebar 16 and the other capable of engaging the top of the arm or ofentering any of the notches 80, and an electrical conductor connectedwith the top of each carbon pencil flattened or enlarged, substantiallyas, and zo for the purposes stated.

HARRY J. W. LLOYD.

Witnesses:

J. RALPH ORWIG, W. R. LANE.

